Suction box



Patented ,lune 4, 1229.

unirsi) STATES PATENT OFFICE.

HARRISGN It. WILLIAMS, F NEW YORK, N. Y.

suc'rron Box.

Application led March 19, 1927. Serial No. 176,675.

. My present invention relates to a suction webs which are too ydense for certain desired purposes,\the chief reason for this being the fact that in such machines, suction is applied belt results.

to the wet web over a large area. In contradistinction to this, I employ a suction box having a single narrow opening extending across the formed web, such box being operated with a comparatively high suction. This high suction has the effect of vwithdrawing the air at high velocity and is effective to carry ofi' a maximum amount of water.l Furthermore, due to the.comparativelygnarrowj arca subjected to suctlon at a given instant, a

minimum of braking action on the travelling In an organization of devices of which my Iimproved suction box 1s adapted to form a part, the web which has thus been partially- -dried is4 fed to a chamber where'it is more or less completely dried by circulating heated air thereover, it being a feature of the assembled devices and of the process "carried out by them that no pressure rollers are used wherevby compressing of the web or felt is avoided.

By means of the type of suction box described just enough cohesion is imparted to the vygeb to enable it to hang together.

In the drawing, Figure 1 shows in vertical' section 'a portion of an illustrative embodiment' of my invention while Figure 2 is a plan ,view on a reduced scale, ofthe device, the belt being indicated in dot-and-dashlinesl As shown, a suction box proper 10 preferably of circular cross section. or atleast of arcuate shape at the top has extending longitudinallythereof a comparatively narrow slit 11. Above the suction box 10 and in contact with` the slit 11 is the ordinary belt or wire 12 hearing a mixture of pulped material and water 13 which has been flowed out -thereupon and which belt has the usual mo'v'e ment of translation tol convey "the web to points where other operations are performed upon it. After considerable experimentation, I have arrived at a width of -slit of from fg to 515 of an inch, a size which I believe to be novel in the art. Box 10 is connected to asource of suction (not shown) through a plpe 14, which has a `cross section at least, as

, larger as the suction area'. By virtue of this construction a high vacuum is applied across a narrow strip of the pulp, so that the air is withdrawn at a high velocity, thus carrying loff the maximum amount of moisture and preventing the slit from becoming clogged by fibers or other particles which may 'enter it. As shown in Figure. 1, due to the circular shape of the box 10, the wire 12 and web 13 lie over and conform to the shape of the box for an appreciable portion of its periphery on either side of slit 11 such overlying portions forming an effective seal therefor.

Preferably I interpose a'shield 15 of say,

hard brass having a cut-out portion accommodating slit 11' whereby to afford a proper bearing action of the wire 12 which in the `usual case is of soft brass. v

As above pointed out, I contemplate employing a fairlystrong suction whereby to compensate for the comparatively small area of suction-to which belt 12 is exposed. The v material which. my improved device is par'- ticularly designedto loperate upon is digested wood pulp or mixtures containing same whereby to prepare the material for subsef 'quent operations which will convert it intoarticles whose requisite qualities include great lightness and vabsorptiveness .such ascatamenlal and surgical pads, wadding and the like'. f What I- claim is.:

' 1. A suction box comprising a box member proper having a narrow slit of substantially from 1g to 51a of an inch extending lon 'tudinally thereof, said `box being adapted. to ex. tend across .the belt of a web making machine.

2. In combination with the wire-oa web making'machine, a suction box lying transversely of `said`.wire, said boxvxhaving anarcuate surface contacting with the wire and a longitudinal, relatively narrow,'suc tion ap'- plying slit intermediate said arcuate portion,

the' parts beingl arranged whereby form an effective seal therefor.

3. In combinatlon wi h 5 he wire of a web e wire -v- I oyerlies said slit at either side thereof so as to making machine, a suction' box lying trans-J versely of saidwire, said box having an ar'- cuate surface contacting with the wire and a;

longitudinal, relatively narrow, suction applying slit intermediate said arcuate o rtion the parts being arranged whereby t e wire lio.'

shaped sealing and shielding member be-v tween the suction box and the wire.

4. A suction box comprising a box member` proper adapted to lie transversely of a web bearing wire, said member being of convex arcuate cross sectionl at the portion adapted to Contact with the Wire and having a narrow longitudinal slit intermediate the arcuate portion.

5. A web-making machine, a wire on which the web is formed, a suctiony boX lying transl versely of said wire, and disposed adjacent the depositing end thereof, whereby said box acts to separate thewater from the deposited pulp and-t0 form a web therefrom, said box being of arcuate cross section at the portion adapted to contact with the wire and having a narrow longitudinal slit intermediate the 20 arcuate portion.

In .testimony whereof I have. aflixe'd 

